1. Field of the Invention
The present invention relates to an image recording device that records a moving image, a method of controlling the image recording device, and a storage medium.
2. Description of the Related Art
In recent years, an image recording device of a digital camera or the like is equipped with a function of shooting and recording a moving image with sound. In such an image device, in shooting and recording a moving image, the moving image is recorded using the frame rate of an image pickup device, i.e. a frame rate during shooting, as a recording frame rate.
The image recording device is further equipped with a function of recording a moving image at a low frame rate, which has been picked up at a high frame rate, and performing slow-motion reproduction of the best moment of the moving image. Further, there is an image recording device that synthesizes and records outputs from a plurality of image pickup devices.
For example, there has been proposed an image recording device that synthesizes image signals output from a plurality of image pickup devices while making the accumulation time period different from each other, into a single image signal to thereby obtain a moving image having a wide dynamic range (see Japanese Patent Laid-Open Publication No. H05-30424).
However, in the image recording device described in Japanese Patent Laid-Open Publication No. H05-30424, the accumulation time period of an image pickup apparatus is limited according to an image pickup frame rate. For this reason, an image picked up at a low illuminance may be darker than expected, and as a result, a desired dynamic range sometimes cannot be obtained.
Further, if a picked-up image is multiplied by a gain to increase the dynamic range, noise is sometimes emphasized in the picked-up image.